1. Field of the Invention
The present invention relates generally to methods of quality control and reliability employed by maintenance supervisors for ensuring safety of components used in a fleet of equipment, and more particularly, to a computerized method for determining a confidence level in a schedule for removing and replacing such component within the fleet.
2. Description of the Related Art
In the field of aircraft maintenance, safety and reliability dictate that maintenance be scheduled at periodic intervals to replace critical components before they fail. Apart from safety concerns, it is generally less expensive and more convenient to take equipment out of service at regular scheduled maintenance intervals to replace components before they fail than to expedite the replacement of a component that has already failed. Particularly in the aircraft industry, unexpected component failures tend to cause flight delays and cancellations that airline companies can ill afford. Safety and reliability concerns are likewise critical for other industries, including commercial trucking, communications, and military weapons and monitoring systems. If component replacement is put off for too long, safety and reliability are compromised, and the cost of post-failure replacement in terms of the potential loss of human life and property damage can be significant. On the other hand, if a component replacement schedule is overly conservative, then maintenance costs are unnecessarily increased by excessive labor and inventory costs; likewise, frequent removal of the equipment from the active fleet also tends to unnecessarily increase the costs of operating the fleet.
Present methods for analyzing the reliability of components in a fleet of vehicles include the simple use of the anticipated life expectancy recommended by the manufacturer of the component. Using this approach, a component is replaced just before the component has been in use for its anticipated life expectancy. However, this simplistic approach typically results in a significant number of components failing. More rigorous approaches have been used in the past, but their complexity, and the difficulty of interpreting their results, has probably discouraged maintenance supervisors from using such methods on any regular basis thus far.
Accordingly, it is an object of the present invention to provide a method for forecasting and analyzing failures of a component installed in a "fleet" of aircraft, trucks, or any other equipment.
Another object of the present invention is to provide such a method that is easy to implement and operate, and which can be repeated and updated at frequent intervals to analyze and adjust component replacement schedules as changed circumstances dictate.
Yet another object of the present invention is to provide such a method that can utilize actual historical data for the reliability of a component under study within a particular fleet in lieu of, and/or in supplementation of, reliability data provided by a manufacturer of such component.
Still another object of the present invention is to provide such a method which permits a manufacturer to reduce the size of its inventory of spare repair/replacement components.
A further object of the present invention is to provide such a method which reliably guides a maintenance supervisor in scheduling component maintenance for convenient, less-expensive, down times but which does not increase maintenance costs by unnecessarily replacing components before it is really necessary to do so.
A still further object of the present invention is to quickly correct reliance upon overly-optimistic life expectancy specifications supplied by the component vendor.
Another object of the present invention is to provide such a method that can be used in conjunction with a component that is incorporated within virtually any type of equipment for which reliability is impacted by the number of operating hours and/or cycles to which the component is subjected.
Still another object of the present invention is to provide such a method which can be performed with the assistance of a conventional desktop or laptop personal computer.
These and other objects of the present invention will become more apparent to those skilled in the art as the description of the present invention proceeds.